The semiconductor integrated circuit (IC) industry has experienced rapid growth. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component that can be created using a fabrication process) has decreased.
Technological advances in IC materials and design have produced various types of ICs that serve different purposes. The fabrication of some types of ICs may require forming a III-V compound layer on a substrate, for example forming a gallium nitride layer on a substrate. These types of IC devices may include high electron mobility transistor (HEMT) devices. However, back-end processes for fabricating a HEMT device typically includes a plurality of plasma-enhanced processes. The processes involve plasma charges that may damage components of the HEMT device, for example a gate component of the HEMT device. When this occurs, the HEMT device may become defective or have degraded performance.
Therefore, while existing methods of fabricating HEMT devices have been generally adequate for their intended purposes, they have not been entirely satisfactory in every aspect.